MECH 200 1st Edition Lecture 2Measurements- Pratt & Whitneyo Improved manufacturing to the point of interchangeable Parts- 1860o No Standard Incho All measurements varied by shop, because measuring tools were not uniform- Eli Whitney (the father of mass production)o Cotton Gin and Milling Machineo He was approached by Samuel Colt to produce 1,000 pistols for the war At this time a feat like this was nearly impossible Mass Production was born- Gage Blockso Standard Unit Blockso Extremely accurateo Used to Calibrate Machines- Micrometer (Mike)o A measurement tool resembling a “C” clampo Measures up to 6” Sizes are: 0”-1”, 1”-2”, 2”-3”, 4”-5”, 5”-6” After 6” calipers are used for measurement- Margino On a threaded piece it refers the raised edgeso Also can be thought of as the widest (Diameter) of the thread - Vernier Caliperso Measuring tool with three ways to measure Between the Jaws From the Hooks (Used for measuring holes) And by using the step- Coordinate Measuring Machineo Extremely expensive piece of equipment that can automatically map a piece being worked on in 3-Dimension- Optical Comparatoro It can be thought of as a Machinist’s microscopeo It is fitted with a Scale that allows you to accurately measure small components- Go/No-Go Gaugeo Used in industry to test if a part meets the manufacturing toleranceso If it fulfills the go the piece is sent to marketo If not it is either machined more, or scrapped- Laser Measuremento This is used in areas where the material is too hot to measure with anytool that would contact the molten material- Shrink Ruleo For patterning/Molds there must be accommodations for the material expansion when hot and shrinkage when